Dear all,
we received "RailML2.2-compliant" infrastructure data but had some
problems parsing it.

There is one element <switch> (within infrastructure ->
tracks->track->trackTopology->connections) which contains an
openEnd-element:> <switch [...]>> <openEnd id="..." code="..."/>> </switch>
Is this compliant to RailML 2.2?
If so, where can I find it within the schema?
If not, is this invalid data with respect to the RailML-2.2-Schema?

From my point of view, railML with an <openEnd> tag under <switch> is
just not valid. I would consider this a bug in the corresponding program.

You didn't say which program produced this, but if it is OpenTrack I
would be interested in knowing more about this bug, since I would have
to fix it. ;-) If this is the case, please feel free to send me a bug
report by email.

just for clarification:
As already indicated by Bernhard an <openEnd> element as a child element
of <switch> is, of course, invalid syntax. Please refer to [1] to find
out that a <switch> must have at least one <connection> element for
defining the connection to a branching track.